Walk-off compensator with tilt function

ABSTRACT

Techniques and structure are disclosed for implementing a spatial walk-off compensation mechanism having an integral tilt function. In some embodiments, the mechanism may comprise a tilt-ball mount having an integrated walk-off compensation medium. In some embodiments, the mechanism may be configured to receive an output beam from a non-linear converter (e.g., optical parametric oscillator or OPO) implementing a non-linear medium comprising a bi-refringent material (e.g., zinc germanium phosphide, or ZnGeP 2 ; cadmium silicon phosphide, or CdSiP 2 ). In some embodiments, the walk-off compensation medium may comprise the same material and/or have the same cut as the non-linear medium. In some embodiments, the mechanism may he manually and/or mechanically adjusted/repositioned to reduce beam walk-off and/or to more precisely direct the beam. In some embodiments, the mechanism may be implemented in mid-infrared (MIR) applications. Numerous configurations and variations will be apparent in light of this disclosure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 61/481,057, filed on Apr. 29, 2011, which isherein incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The invention relates to lasers, and more particularly to spatialwalk-off compensation.

BACKGROUND

In some non-linear converter applications, emissions from a non-linearconverter such as an optical parametric oscillator (OPO), for example,may drift apart or otherwise fail to properly overlap—a phenomenon knownas spatial walk-off. Efforts may be made to compensate for walk-off, andso make emissions from a non-linear converter better overlap. However,there are a number of non-trivial challenges to achieving walk-offcompensation.

SUMMARY

One embodiment of the present invention provides an apparatus includinga tilt-ball mount having a through-hole aperture formed therein and awalk-off compensation medium, wherein at least a portion of the walk-offcompensation medium is disposed within the through-hole aperture of thetilt-ball mount. In some cases, the tilt-ball mount has a geometry thatis spherical, cylindrical, ellipsoidal, polyhedral, or prismatic. Insome cases, the tilt-ball mount is configured to be tilted and/orrolled. In some cases, the walk-off compensation medium comprises a zincgermanium phosphide (ZnGeP₂) crystal or a cadmium silicon phosphide(CdSiP₂) crystal. In some cases, the walk-off compensation medium has ageometry that is polyhedral, prismatic, or cylindrical. In some cases,the apparatus is configured to receive a beam from a non-linearconverter and to achieve at least one of beam walk-off compensationand/or precision beam directing. In some such cases, the non-linearconverter comprises an optical parametric oscillator (OPO), in someother such cases, the non-linear converter utilizes a non-linear mediumcomprising a zinc germanium phosphide (ZnGeP₂) crystal and/or a cadmiumsilicon phosphide (CdSiP₂) crystal. In some other such cases, theapparatus further includes a stabilizer configured to minimize and/orprevent movement of the tilt-ball mount once in a desired positioned.

Another embodiment of the present invention provides a system includinga non-linear converter configured to receive a pump beam and generate anoutput beam and a walk-off compensation mechanism having an integraltilt function, wherein the walk-off compensation mechanism is configuredto be tilted and/or rolled to achieve at least one of walk-offcompensation and/or precision directing for the output beam. In somecases, the non-linear converter comprises an optical parametricoscillator (OPO). In some cases, the non-linear converter utilizes anon-linear medium comprising a zinc germanium phosphide (ZnGeP₂) crystaland/or a cadmium silicon phosphide (CdSiP₂) crystal of a given cut. Insome cases, the walk-off compensation mechanism includes a tilt-ballmount having a through-hole aperture formed therein and a walk-offcompensation medium, wherein at least a portion of the walk-offcompensation medium is disposed within the through-hole aperture of thetilt-ball mount. In some cases, the tilt-ball mount has a geometry thatis spherical, cylindrical, ellipsoidal, polyhedral, or prismatic. Insome other such cases, the walk-off compensation medium comprises a zincgermanium phosphide (ZnGeP₂) crystal or a cadmium silicon phosphide(CdSiP₂) crystal. In some other such cases, the walk-off compensationmedium at least one of comprises the same material as the non-linearmedium and/or has the same cut as the non-linear medium. In some othersuch cases, the system further includes a stabilizer, wherein thestabilizer includes a seat configured to receive a first portion of thetilt-ball mount, a chassis configured to support the seat, a postoperatively coupled to the chassis, a clamp arm, operatively coupled tothe post, wherein the clamp arm is configured to engage a second portionof the tilt-ball mount, and a fastener configured to secure the clamparm once it engages the second portion of the tilt-ball mount.

Another embodiment of the present invention provides a method includingthe steps of producing a beam with a non-linear converter utilizing anon-linear medium comprising a bi-refringent material of a given cut,directing the beam to a walk-off compensation mechanism having anintegral tilt function and configured to be tilted and/or rolled toachieve at least one of walk-off compensation and/or precision directingfor the beam, wherein the walk-off compensation mechanism includes atilt-ball mount having a through-hole aperture formed therein and awalk-off compensation medium that at least one of comprises the samebi-refringent material as the non-linear medium and/or has the same cutas the non-linear medium, wherein at least a portion of the walk-offcompensation medium is disposed within the through-hole aperture of thetilt-ball mount, and adjusting the walk-off compensation mechanism tocompensate for beam walk-off and/or to precisely direct the beam. Insome cases, the non-linear converter comprises an optical parametricoscillator (OPO). In some cases, the non-linear medium comprises a zincgermanium phosphide (ZnGeP₂) crystal and/or a cadmium silicon phosphide(CdSiP₂) crystal.

The features and advantages described herein are not all-inclusive and,in particular, many additional features and advantages will be apparentto one of ordinary skill in the art in view of the drawings,specification, and claims. Moreover, it should be noted that thelanguage used in the specification has been selected principally forreadability and instructional purposes and not to limit the scope of theinventive subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram depicting an example approach to providingwalk-off compensation.

FIG. 2 is a block diagram of a laser cavity implementing a walk-offcompensation mechanism configured in accordance with an embodiment ofthe present invention.

FIG. 3A illustrates a perspective view of a walk-off compensationmechanism configured in accordance with an embodiment of the presentinvention.

FIG. 3B illustrates a cross-section view of the walk-off compensationmechanism of FIG. 3A taken along dashed line β-β therein.

FIG. 4 is a perspective view of a walk-off compensation mechanism with astabilizer, configured in accordance with an embodiment of the presentinvention.

These and other features of the present embodiments will be understoodbetter by reading the following detailed description, taken togetherwith the figures herein described. The accompanying drawings are notintended to be drawn to scale. In the drawings, each identical or nearlyidentical component that is illustrated in various figures isrepresented by a like numeral. For purposes of clarity, not everycomponent may be labeled in every drawing.

DETAILED DESCRIPTION

Techniques and structure are disclosed for implementing a spatialwalk-off compensation mechanism having an integral tilt function. Insome embodiments, the mechanism may comprise a tilt-ball mount having anintegrated walk-off compensation medium. In some embodiments, themechanism may be configured to receive an output beam from a non-linearconverter (e.g., optical parametric oscillator or OPO) implementing anon-linear medium comprising a bi-refringent material (e.g., zincgermanium phosphide, or ZnGeP₂; cadmium silicon phosphide, or CdSiP₂).In some embodiments, the walk-off compensation medium may comprise thesame material and/or have the same cut as the non-linear medium. In someembodiments, the mechanism may be manually and/or mechanicallyadjusted/repositioned to reduce beam walk-off and/or to more preciselydirect the beam. In some embodiments, the mechanism may be implementedin mid-infrared (MIR) applications. Numerous configurations andvariations will be apparent in light of this disclosure.

General Overview

As will be appreciated, a non-linear converter (e.g., an opticalparametric oscillator or OPO) which implements an anisotropic medium(e.g., a single crystal of a bi-refringent material), for example, issusceptible to producing output beams which experience a phenomenonknown as beam walk-off, wherein the emissions drift apart or otherwisefail to properly overlap. In such cases, the waves interacting within afocused beam lose their spatial overlap during propagation, and thus theoutput beams may have, for instance, a broader amplitude and/or broaderintensity profile than desired for a given application.

As will further be appreciated, OPOs which implement, for example, asingle crystal of a bi-refringent material (e.g., zinc germaniumphosphide, ZnGeP₂ or ZGP; cadmium silicon phosphide or CdSiP₂) aresusceptible to producing output beams which experience beam walk-off;that is, the beam centroid of the residual pump beam at the exit of theOPO is physically displaced from the centroids of the signal and idlerbeams produced by the OPO, which may cause problems for a telescope thatreceives the beams.

Walk-off compensation may be utilized to reduce/mitigate beam walk-off(e.g., make the emissions from a non-linear converter better overlap).For instance, FIG. 1 is a block diagram depicting an example approach toproviding walk-off compensation. As can be seen, a laser cavity 100 mayinclude, for example, a non-linear converter 110 (e.g., OPO)implementing a high-reflectivity mirror 120 at its input, apartial-reflectivity mirror 140 at its output, and a non-linear medium130 (e.g., a non-linear crystal) there between. A pump beam may beprovided to the non-linear converter 110 at its input coupler (e.g.,incident to the high-reflectivity mirror 120). To provide walk-offcompensation, a walk-off compensation medium 150 (e.g., a crystal) ispositioned downstream of the non-linear converter 110 and configured toreceive its output (e.g., exiting the partial-reflectivity mirror 140).The walk-off compensation crystal 150 is of the same type and cut asthat utilized as non-linear medium 130. In addition, a separate,discrete tilt-ball 154 is further included downstream of the walk-offcompensation medium 150 and configured to receive its output. Thetilt-ball 154 comprises a metal ball having a thick piece of glass(e.g., zinc selenide, silicon, germanium, silicon germanium, orsapphire) secured therein, into which the output beam of the walk-offcompensation medium 150 is directed. Upon tilting the tilt-ball 154, thebeam may be directed, for instance, to a next stage or other locationwhere it can be further processed or otherwise utilized.

However, such a design is associated with a number of non-trivial issuesand complications. For example, implementing tilt-ball 154 and walk-offcompensation crystal 150 as separate, discrete optical components: (1)increases the overall size of laser cavity 100; (2) increases theoverall bulk, footprint, and/or weight of a laser system implementingsuch a laser cavity 100; (3) reduces the dependability of the lasersystem implementing such a laser cavity 100, given that there are moreoptical components which may malfunction and/or degrade over time; and(4) reduces the integrity of the output beam, given that overall beamloss increases as the number of optical components disposed in the beamline increases. Other inherent complications and non-trivial issuesassociated with laser cavity designs implementing tilt-balls 154 andseparate, discrete walk-off compensation media 150 will be apparent inlight of this disclosure.

Therefore, there is need for techniques for providing spatial walk-offcompensation while reducing the number of optical components in the beamline, minimizing the size of a given laser cavity, and/or minimizing thebulk, footprint, and/or weight of a given laser system.

Thus, and in accordance with an embodiment of the present invention,techniques are disclosed for implementing a walk-off compensator havingan integral tilt function. In some embodiments, a walk-off compensationmedium (e.g., crystal of a given material and cut) may be integratedinto or otherwise operatively coupled with a tilt-ball mount, forexample. The resultant mechanism may he implemented, in someembodiments, downstream of a non-linear converter (e.g., opticalparametric oscillator or OPO) to redirect its output beam to help itsemissions achieve a desired degree of overlap (e.g., minimize/eliminatebeam walk-off). In accordance with an embodiment, the mechanism may bemanually and/or mechanically adjusted to achieve the desired beamredirection.

In accordance with an embodiment, techniques disclosed herein may beimplemented, for example, in a laser cavity configured for use inmid-infrared (MIR) (e.g., in the range of about 3-8 μm) applications.However, the claimed invention is not so limited; for instance, and inaccordance with an embodiment of the present invention, techniquesdisclosed herein may be implemented in any application where spatialwalk-off results, for example, front bi-refringence of a non-linearmedium.

As will be appreciated, implementation of a walk-off compensator havingan integral tilt function, in accordance with an embodiment, mayeliminate the need for inclusion of a separate, discrete tilt-ballcomponent (e.g., such as the tilt-ball 154 of FIG. 1). Thus, and inaccordance with an embodiment, one or more of the followingbenefits/advantages may be realized: (1) a reduction in the overall sizeof the laser cavity which includes such a walk-off compensator having anintegral tilt function; (2) a reduction in the overall bulk, footprint,and/or weight of a laser system implementing such a laser cavity; (3) anincrease in the dependability of such a laser system, given that thereare comparatively fewer optical components which may malfunction and/ordegrade over time; and/or (4) an increase in the integrity of the outputbeam, given that overall beam loss decreases as the number of opticalcomponents disposed in the beam line decreases. Otherbenefits/advantages associated with one or more embodiments of thepresent invention will depend on a given application and will beapparent in light of this disclosure.

System Architecture and Operation

FIG. 2 is a block diagram of a laser cavity 200 implementing a walk-offcompensation mechanism 250 configured in accordance with an embodimentof the present invention. As can be seen, laser cavity 200 may include,for example, a non-linear converter 210 (e.g., an optical parametricoscillator or OPO) which suffers from beam walk-off (e.g., due tobi-refringence of its non-linear medium 230). In some embodiments, awalk-off compensation mechanism. 250 may be implemented downstream ofnon-linear converter 210. Laser cavity 200 may include additional,fewer, and/or different elements or components from those heredescribed, as will be appreciated in light of this disclosure. Theclaimed invention is not intended to be limited to any particular lasercavity or laser system configurations, but can be used with numerousconfigurations in numerous applications, as will be appreciated in lightof this disclosure.

In accordance with an embodiment, a pump beam may be provided tonon-linear converter 210 by any suitable pump laser source, including,but not limited to: a fiber laser (e.g., a thulium-doped fiber laser); asemiconductor diode laser (e.g., gallium arsenide or GaAs; indiumphosphide or InP); and/or a solid-state laser (e.g., Q-switched Ho:YAG;Lu:YAG). The pump beam may be of any given wavelength or range ofwavelengths (e.g., less than about 2 μm) and may be continuous wave (CW)or pulsed (e.g., if non-linear converter 210 is an OPO), in accordancewith an embodiment, as suitable for a given application. Other suitablesources and/or wavelengths of the pump beam will be apparent in light ofthis disclosure.

As can be seen, the pump beam may be received at an input end ofnon-linear converter 210, which may include, for example, ahigh-reflectivity mirror 220 or other input coupler. As will beappreciated, high-reflectivity mirror 220 may be configured/implementedas conventionally done. For instance, in one specific exampleembodiment, high-reflectivity mirror 220 may be configured/implementedas a zinc selenide (ZnSe) substrate having one or more suitablehigh-reflectivity coatings. Other suitable configurations/types ofhigh-reflectivity mirror 220 will depend on a given application and/orother componentry of non-linear converter 210 (e.g., a correspondingpartial-reflectivity mirror 240, discussed in detail below) and will beapparent in light of this disclosure.

As can further be seen, the beam subsequently may be received by anon-linear medium 230. In accordance with an embodiment, non-linearmedium 230 may be, for example, a high-refractive-index, bi-refringentmaterial such as, but not limited to zinc germanium phosphide (ZnGeP₂ orZGP); and/or cadmium silicon phosphide (CdSiP₂). In some embodiments,non-linear medium 230 may be implemented as a single crystal of a givencut. In some cases, and in accordance with an embodiment, the typeand/or cut of non-linear medium 230 may be chosen, at least in part,based on the desired output wavelength range (e.g., MIR) of non-linearconverter 210. Other suitable materials and/or configurations fornon-linear medium 230 will depend on a given application and will beapparent in light of this disclosure.

As can further be seen, after passage through non-linear medium 230, thebeam may be directed to an output end of non-linear converter 210, whichmay include, for example, a partial-reflectivity mirror 240 or otheroutput coupler. As with the aforementioned high-reflectivity mirror 220,partial-reflectivity mirror 240 may be configured/implemented asconventionally done. For instance, in one specific example embodiment,partial-reflectivity mirror 240 may be configured/implemented as a zincselenide (ZnSe) substrate having one or more suitablepartial-reflectivity coatings. In some instances, the type, geometry,and/or configuration of partial-reflectivity mirror 240 may be chosen,at least in part, based on the type, geometry, and/or configuration ofhigh-reflectivity mirror 220. Other suitable configurations/types ofpartial-reflectivity mirror 240 will depend on a given application andwill be apparent in light of this disclosure.

Upon exiting non-linear converter 210, the beam may be made availablefor further processing and/or utilization. However, as previously noted,at this stage the beam may exhibit spatial walk-off effects (e.g., theemissions may drift apart or otherwise fail to properly/desirablyoverlap, resulting in a broader amplitude and/or a broader intensityprofile than desired), which may make the beam unsuitable for someapplications or otherwise cause problems for a telescope that receivesthe beams. Therefore, as will be appreciated, it may be desirable toimplement one or more walk-off compensation techniques disclosed hereinto mitigate/eliminate the effects of beam walk-off.

Thus, and in accordance with an embodiment of the present invention, awalk-off compensation mechanism 250 may be implemented downstream ofnon-linear converter 210 and configured, for example, to receive itsoutput beam and perform one or more functions including, but not limitedto: (1) beam walk-off compensation; and/or (2) precision beam direction.In some cases, walk-off compensation mechanism 250 may help tominimize/eliminate the walk-off effect associated, for example, with anon-linear converter 210 (e.g., an OPO) implementing a single crystal ofbi-refringent material ZGP or CdSiP₂) as its non-linear medium 230.Other suitable configurations/uses for walk-off compensation mechanism250 will depend on a given application and will be apparent in light ofthis disclosure.

FIG. 3A illustrates a perspective view of a walk--off compensationmechanism 250 configured in accordance with an embodiment of the presentinvention, and FIG. 3B illustrates a cross-section view of thecompensation mechanism 250 of FIG. 3A taken along dashed line β-βtherein. As can be seen, walk-off compensation mechanism 250 may includea walk-off compensation medium 252, which, in accordance with anembodiment, may comprise the same material and/or be configured with thesame cut as, for example, non-linear medium 230 implemented upstream innon-linear converter 210 (e.g., ZGP and/or CdSiP₂), discussed in detailbelow.

In accordance with an embodiment, walk-off compensation medium 252 maybe of any desired dimensions (e.g., length, width, height,circumference, etc.) and/or geometry (e.g., polyhedral, prismatic,cylindrical, etc.) suitable for a given application and may be chosen,at least in part, based on the desired amount of beam displacement(e.g., the beam centroid spatial translation to be achieved to yield thedesired amount of beam overlapping). In one specific example embodiment,walk-off compensation medium 252 may be configured as, for example, as asquare prism (e.g., length in the range of about 5-15 mm; cross-sectionarea in the range of about 16-25 mm²). Other suitable dimensions,geometries, and/or configurations for walk-off compensation medium 252will depend on a given application and will be apparent in light of thisdisclosure.

As previously noted, a non-linear converter 210 (e.g., OPO) whichimplements, for example, a single crystal of a bi-refringent material(e,g, zinc germanium phosphide, ZnGeP₂ or ZGP; cadmium silicon phosphideor CdSiP₂) as its non-linear medium 230 may be susceptible to producingoutput beams which experience beam walk-off. Thus, and in accordancewith a specific example embodiment, in some cases in which non-linearmedium 230 is a single crystal of ZGP or CdSiP₂ of a given cut, walk-offcompensation medium 252 similarly may comprise a single crystal of ZGPor CdSiP₂, respectively, of the same cut.

Given that walk-off compensation medium 252 is external to or otherwisediscrete from non-linear converter 210 (e.g., not part of the resonator,and so subjected to lower beam intensity), in accordance with anembodiment, it may be of lower quality (e.g., lower purity, lowercoating quality, and/or lower damage threshold, etc.) than non-linearmedium 230.

As can farther be seen, in some embodiments, walk-off compensationmechanism 250 may include a tilt-ball mount 254. In accordance with anembodiment, tilt-ball mount 254 may comprise, for example, a metal(e.g., aluminum, stainless steel, titanium, etc.) or other suitablematerial that is compatible, for instance, with walk-off compensationmedium 252, tilt-ball seat 285 (discussed in detail below), and/or anoptionally included quantity of adhesive (discussed in detail below).Furthermore, and in accordance with an embodiment, tilt-ball mount 254may be of any desired dimensions (e.g., length, width, height,circumference, etc.) and/or geometry (e.g., spherical, cylindrical,ellipsoidal, polyhedral, prismatic, etc.) suitable for a givenapplication and may be chosen, at least in part, based on the desiredamount of beam displacement (e.g., the beam centroid spatial translationto be achieved to yield the desired amount of beam overlapping). In onespecific example embodiment, tilt-ball mount 254 may be configured, forexample as a 10-12 mm diameter sphere and/or be capable ofmoving/displacing the beam by about 1 mm. Other suitable materials,dimensions, geometries, and/or configurations for tilt-ball mount 254will depend on a given application and will be apparent in light of thisdisclosure. For example, tilt-hall mount 254 alternatively may beconfigured as a tip-tilt mount or an azimuth over elevation yolk.

In some embodiments, tilt-ball mount 254 may be configured with anaperture, recess, or other feature formed therein and designed toreceive/retain at least a portion of walk-off compensation medium 252.For instance, in one specific example embodiment, tilt-ball mount 254includes a through-hole aperture 255 that is appropriately dimensionedto securely receive/mount walk-off compensation medium 252 (e.g., thedimensions and/or geometry of through-hole aperture 255 may be made toaccommodate those of walk-off compensation medium 252). In someembodiments, through-hole aperture 255 may be configured to provide afriction fit that suitably secures/mounts walk-off compensation medium252 within/on tilt-ball mount 254. In some embodiments, through-holeaperture 255 may be configured to receive, for example, an epoxy orother appropriate adhesive substance that helps to secure/mount walk-offcompensation medium 252 within/on tilt-ball mount 254. Other materialsand/or configurations for keeping walk-off compensation medium 252within through-hole aperture 255 will depend on a given application andwill be apparent in light of this disclosure.

In accordance with an embodiment, tilt-ball mount 254 may be configuredto be adjusted (e.g., tilted, rolled, etc.) and/or mechanically toreposition walk-off compensation medium 252 (e.g., relative to theoutput beam of non-linear converter 210). In some embodiments, tilt-ballmount 254 may provide/imbue walk-off compensation mechanism 250 with anintegral tilt function, which may permit, for example, precision beamdirecting to help achieve sufficient overlap (e.g., beam centroidspatial translation to mitigate beam spatial walk-off) of the emissionsfrom non-linear converter 210 (e.g., OPO), for instance, in the farfield.

In some cases, it may be desirable to adjust tilt-ball mount 254 to agiven angle that is, in one specific example embodiment, the exactopposite angle of non-linear medium 230 implemented upstream innon-linear converter 210. However, the claimed invention is not solimited; for instance, and in accordance with an embodiment of thepresent invention, so long as walk-off compensation medium 252 isproperly oriented within tilt-ball mount 254 (e.g., the walk-offcompensation crystal 252 is correctly inserted front-to-hack withinthrough-hole aperture 255 of tilt-ball mount 254), walk-off compensationmechanism 250 may be capable of being adjusted several degrees withoutsignificantly changing the quality of the walk-off compensation (e.g.,still achieve the desired beam centroid spatial translation to mitigatebeam spatial walk-off).

As will be appreciated, if walk-off compensation medium 252 comprises ahigh-refractive-index material (e.g., a ZGP or CdSiP₂ crystal) and is ofsufficient length, then adjustment of tilt-bail 254 including suchwalk-off compensation medium 252 may result in significant displacementof all output beams together. Thus, and in accordance with anembodiment, this may be useful for applications which require that theoutput beams be centered with respect to the output telescope lenses,for example.

As previously noted, and in accordance with an embodiment of the presentinvention, combination of a walk-off compensation medium 252 with atilt-ball mount 254 to produce a walk-off compensator mechanism 250having an integral tilt function may eliminate, for example, the need toinclude within a given laser system a tilt-bail (with its attendantthick glass piece) that is separate and discrete from its walk-offcompensation medium (e.g., such as with the example approach representedin FIG. 1).

As previously noted, tilt-ball mount 254 may be adjusted manually and/ormechanically into a given position that yields the desired output beam(e.g., as indicated by test equipment monitoring the output beam). Aswill be appreciated, it may be desirable to minimize/prevent anysubsequent, unwanted movement of tilt-ball mount 254 (and thus walk-offcompensation medium 252) once a desired position/orientation isachieved. Thus, and in accordance with an embodiment, a stabilizer(e.g., physical clamp, magnetic clamp, shim, adhesive/glue, etc.) may beimplemented to secure/stabilize walk-off compensation mechanism 250 in agiven position temporarily and/or permanently. However, the claimedinvention is not so limited; for example, and in accordance with anembodiment, in some cases proper balancing of the tilt-ball mount 254may be sufficient to prevent such unwanted movement.

FIG. 4 is a perspective view of a walk-off compensation mechanism 250with a stabilizer 280, configured in accordance with an embodiment ofthe present invention. As can be seen, walk-off compensation mechanism250 (e.g., tilt-ball mount 254) may be seated in or otherwise adjustablycoupled with, for example, a tilt-ball seat 285. Tilt-ball seat 285 maybe configured to permit tilt-bail 254 (and thus walk-off compensationmedium 252) to be adjusted (e.g., tilted, rolled, etc.) to achieve avariety of positions/orientations, in accordance with an embodiment. Ascan further be seen, tilt-ball seat 285 may be secured or otherwiseintegrated into a chassis 286 or other suitable structure/support.

Once in the desired position/orientation, a clamping mechanism, forexample, may he implemented to engage and secure/stabilize tilt-ballmount 254 (and thus walk-off compensation medium 252) in a givenorientation. For instance, and in accordance with one specific exampleembodiment, the clamping mechanism may comprise a post 287, a clamp arm288, and a fastener 289. Clamp arm 288 may be brought into contact witha portion of walk-off compensation mechanism 250 (e.g., the exteriorsurface of tilt-ball mount 254) and may be held at (e.g., locked into)such location by fastener 289 (e.g., a screw, threaded bolt, or othersuitable fastener, etc.), which is received by a corresponding portionof post 287. Consequently, tilt-ball mount 254 (and thus walk-offcompensation medium 252) may be held/stabilized in position withintilt-ball seat 285. Other suitable configurations and/or stabilizercomponents will depend on a given application and will be apparent inlight of this disclosure.

As will be appreciated in light of this disclosure, a ball-in-seatconfiguration (e.g., walk-off compensation mechanism 250 adjustablycoupled with stabilizer 280) may be implemented, for example, inapplications where a wide displacement range is desired. In some otherembodiments in which only a small range of displacement is desired,walk-off compensation mechanism 250 may be operatively coupled, forexample, with an azimuth/elevation flexure arrangement.

The foregoing description of the embodiments of the invention has beenpresented for the purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Many modifications and variations are possible in light ofthis disclosure. It is intended that the scope of the invention belimited not by this detailed description, but rather by the claimsappended hereto.

What is claimed is:
 1. An apparatus comprising: a tilt-ball mount havinga through-hole aperture formed therein; and a walk-off compensationmedium, wherein at least a portion of the walk-off compensation mediumis disposed within the through-hole aperture of the tilt-ball mount 2.The apparatus of claim 1, wherein the tilt-ball mount has a geometrythat is spherical, cylindrical, ellipsoidal, polyhedral, or prismatic.3. The apparatus of claim 1, wherein the tilt-bail mount is configuredto be tilted and/or rolled.
 4. The apparatus of claim 1, wherein thewalk-off compensation medium comprises a zinc germanium phosphide(ZnGeP₂) crystal or a cadmium silicon phosphide (CdSiP₂) crystal.
 5. Theapparatus of claim 1, wherein the walk-off compensation medium has ageometry that is polyhedral, prismatic, or cylindrical.
 6. The apparatusof claim 1, wherein the apparatus is configured to receive a beam from anon-linear converter and to achieve at least one of beam walk-offcompensation and/or precision beam directing,
 7. The apparatus of claim6, wherein the non-linear converter comprises an optical parametricoscillator (OPO).
 8. The apparatus of claim 6, wherein the non-linearconverter utilizes a non-linear medium comprising a zinc germaniumphosphide (ZnGeP₂) crystal and/or a cadmium silicon phosphide (CdSiP₂)crystal.
 9. The apparatus of claim 6 further comprising a stabilizerconfigured to minimize and/or prevent movement of the tilt-ball mountonce in a desired positioned.
 10. A system comprising: a non-linearconverter configured to receive a pump beam and generate an output beam;and a walk-off compensation mechanism having an integral tilt function.,wherein the walk-off compensation mechanism is configured to be tiltedand/or rolled to achieve at least one of walk-off compensation and/orprecision directing for the output beam.
 11. The system of claim 10,wherein the non-linear converter comprises an optical parametricoscillator (OPO).
 12. The system of claim 10, wherein the non-linearconverter utilizes a non-linear medium comprising a zinc germaniumphosphide (ZnGeP₂) crystal and/or a cadmium silicon phosphide (CdSiP₂)crystal of a given cut.
 13. The system of claim 10, wherein the walk-offcompensation mechanism comprises: a tilt-ball mount having athrough-hole aperture formed therein; and a walk-off compensationmedium, wherein at least a portion of the walk-off compensation mediumis disposed within the through-hole aperture of the tilt-ball mount 14.The system of claim 13, wherein the tilt-ball mount has a geometry thatis spherical, cylindrical, ellipsoidal, polyhedral, or prismatic. 15.The system of claim 13, wherein the walk-off compensation mediumcomprises a zinc germanium phosphide (ZnGeP₂) crystal or a cadmiumsilicon phosphide (CdSiP₂) crystal.
 16. The system of claim 13, whereinthe walk-off compensation medium at least one of comprises the samematerial as the non-linear medium and/or has the same cut as thenon-linear medium.
 17. The system of claim 13 ⁻further comprising astabilizer, wherein the stabilizer comprises: a seat configured toreceive a first portion of the tilt-ball mount; a chassis configured tosupport the seat; a post operatively coupled to the chassis; a clamp armoperatively coupled to the post, wherein the chimp arm is configured toengage a second portion of the tilt-ball mount; and a fastenerconfigured to secure the clamp arm once it engages the second portion oftilt-ball mount.
 18. A method comprising: producing a beam with anon-linear converter utilizing a non-linear medium comprising abi-refringent material of a given cut; directing the beam to a walk-offcompensation mechanism having an integral tilt function and configuredto be tilted and/or rolled to achieve at least one of walk-offcompensation and/or precision directing for the beam, wherein thewalk-off compensation mechanism comprises: a tilt-ball mount having athrough-hole aperture formed therein; and a walk-off compensation mediumthat at least one of comprises the same bi-refringent material as thenon-linear medium and/or has the same cut as the non-linear medium,wherein at least a portion of the walk-off compensation medium isdisposed within the through-hole aperture of the tilt-ball mount; andadjusting the walk-off compensation mechanism to compensate for beamwalk-off and/or to precisely direct the beam.
 19. The method of claim18, wherein the non-linear converter comprises an optical parametricoscillator (OPO)
 20. The method of claim 18, wherein the non-linearmedium comprises a zinc germanium phosphide (ZnGeP₂) crystal and/or acadmium silicon phosphide (CdSiP₂) crystal.